The present disclosure relates to a technique for peeling a recording paper sheet off an image carrier.
In a general image forming apparatus, a toner image is formed on a photosensitive drum (image carrier), the photosensitive drum is rotated with a transfer roller pressed against the photosensitive drum to form a nip area between the photosensitive drum and the transfer roller, a recording paper sheet is caught in the nip area to transfer the toner image from the photosensitive drum to the recording paper sheet, and the toner image on the recording paper sheet is then fixed by the application of heat and pressure.
After passing through the nip area, the recording paper sheet is peeled off the photosensitive drum and further conveyed. However, if the recording paper sheet cannot be peeled off the photosensitive drum, it wraps around the photosensitive drum and becomes jammed. To cope with this, separating claws are provided downstream of the nip area in the direction of conveyance of the recording paper sheet to rest against the surface of the photosensitive drum. The separating claws can certainly peel the recording paper sheet off the photosensitive drum.
There are known many image forming apparatuses provided with such separating claws. Among them, an image forming apparatus is proposed in which a sheet trailing end restricting member is provided to extend beyond each separating claw toward a conveyance path for a recording paper sheet so that when the trailing end portion of the recording paper sheet comes close to the separating claw, it strikes the sheet trailing end restricting member but does not strike the separating claw. Toner remaining on the surface of the photosensitive drum sometimes adheres to and becomes deposited on the separating claws. If in this situation the trailing end portion of the recording paper sheet strikes the separating claws, it is contaminated with the toner. The sheet trailing end restricting members are provided in order to prevent such contamination of the trailing end portion of the recording paper sheet.
Alternatively, a star-shaped roller is provided to extend beyond each separating claw toward the conveyance path for the recording paper sheet so that the trailing end portion of the recording paper sheet can strike the star-shaped roller but does not strike the separating claw, thus preventing contamination of the trailing end portion of the recording paper sheet.